PubMed Health⌕ Search

Biomedical subjects

P Sipilä

Publications and source records attributed to P Sipilä.

At least 19 recordsLinked to original sources
PubMed2003

Characterisation of projectiles composed of depleted uranium.

Projectiles suspected to be composed of depleted uranium (DU) were found in Kosovo. Their properties were analysed using alpha and gamma ray spectrometry, mass spectrometry and electron microscopy. They were found to be composed of DU with small amounts of other elements such as Ti. 236U was detected in the penetrators, reflecting the use of reprocessed fuel. No transuranium elements were detected. The typical external dose rate meter is not the best option for mapping the location of penetrators from the ground. Monte Carlo calculations were performed in estimating possible skin doses. Penetrators in long-lasting contact with skin may cause a notable equivalent dose to skin.

Environmental Exposure↗
PubMed2001

Dosimetry of beta-ray ophthalmic applicators: comparison of different measurement methods.

An international intercomparison of the dosimetry of three beta particle emitting ophthalmic applicators was performed, which involved measurements with radiochromic film, thermoluminescence dosimeters (TLDs), alanine pellets, plastic scintillators, extrapolation ionization chambers, a small fixed-volume ionization chambers, a diode detector and a diamond detector. The sources studied were planar applicators of 90Sr-90Y and 106Ru-106Rh, and a concave applicator of 106Ru-106Rh. Comparisons were made of absolute dosimetry determined at 1 mm from the source surface in water or water-equivalent plastic, and relative dosimetry along and perpendicular to the source axes. The results of the intercomparison indicate that the various methods yield consistent absolute dosimetry results at the level of 10%-14% (one standard deviation) depending on the source. For relative dosimetry along the source axis at depths of 5 mm or less, the agreement was 3%-9% (one standard deviation) depending on the source and the depth. Crucial to the proper interpretation of the measurement results is an accurate knowledge of the detector geometry, i.e., sensitive volume and amount of insensitive covering material. From the results of these measurements, functions which describe the relative dose rate along and perpendicular to the source axes are suggested.

Alanine↗
PubMed2001

Calculation of beta-ray dose distributions from ophthalmic applicators and comparison with measurements in a model eye.

Dose distributions throughout the eye, from three types of beta-ray ophthalmic applicators, were calculated using the EGS4, ACCEPT 3.0, and other Monte Carlo codes. The applicators were those for which doses were measured in a recent international intercomparison [Med. Phys. 28, 1373 (2001)], planar applicators of 106Ru-106Rh and 90Sr-90Y and a concave 106Ru-106Rh applicator. The main purpose was to compare the results of the various codes with average experimental values. For the planar applicators, calculated and measured doses on the source axis agreed within the experimental errors (<10%) to a depth of 7 mm for 106Ru-106Rh and 5 mm for 90Sr-90Y. At greater distances the measured values are larger than those calculated. For the concave 106Ru-106Rh applicator, there was poor agreement among available calculations and only those calculated by ACCEPT 3.0 agreed with measured values. In the past, attempts have been made to derive such dose distributions simply, by integrating the appropriate point-source dose function over the source. Here, we investigated the accuracy of this procedure for encapsulated sources, by comparing such results with values calculated by Monte Carlo. An attempt was made to allow for the effects of the silver source window but no corrections were made for scattering from the source backing. In these circumstances, at 6 mm depth, the difference in the results of the two calculations was 14%-18% for a planar 106Ru-l06Rh applicator and up to 30% for the concave applicator. It becomes worse at greater depths. These errors are probably caused mainly by differences between the spectrum of beta particles transmitted by the silver window and those transmitted by a thickness of water having the same attenuation properties.

Beta Particles↗
PubMed2001

Mometasone furoate nasal spray in the treatment of perennial non-allergic rhinitis: a nordic, multicenter, randomized, double-blind, placebo-controlled study.

In order to evaluate the efficacy and safety of mometasone furoate nasal spray (MFNS) in patients with perennial non-allergic rhinitis (PNAR) a phase III, double-blind, randomized, placebo-controlled, Nordic multicenter study was performed at 16 sites (7 in Sweden, 3 in Denmark, 3 in Finland and 3 in Norway). A total of 329 patients (age 18-82 years) with a mean duration of PNAR of 9 years were included in the study. The total duration of the study was 11 weeks: 2 weeks of screening, 6 weeks of treatment and 3 weeks of follow-up. Inclusion criteria were unspecific rhinitis symptoms and exclusion criteria were a positive skin prick test as well as intolerance to aspirin or non-steroidal anti-inflammatory drugs. Endoscopy was performed to exclude patients with structural anomalies and nasal polyps. The primary efficacy variable was the subject's total overall evaluation. In the intention-to-treat (ITT) group of patients (n = 329) the improvement rates were 56% (MFNS) and 49% (placebo). In the per-protocol (PP) group (n = 251) the corresponding figures were 58% and 47%. Stratifying for groups of patients having moderate symptoms, the results were 54% vs 43% in the ITT group and 56% vs 41% in the PP group. The therapeutic response showed greater improvement in total nasal score as recorded by the investigator in the groups treated with MFNS as compared to the placebo group (p = 0.09 [PP], p = 0.14 [ITT]). Adverse events occurred during the study, upper respiratory tract infections and headache being the most frequently reported, but there was no statistically significant difference between MFNS and placebo. The results of this study indicate that MFNS is a safe and effective treatment for patients with PNAR.

Administration, Intranasal↗
PubMed1999

Distractible children show abnormal orienting to non-attended auditory stimuli.

Event-related potentials were recorded in response to intermittently presented, non-attended trains of identical auditory stimuli in healthy 9-year-old children. In abnormally distractible children (n =24), the first tone in each train elicited a significantly larger N1 vertex response than in the non-distractible children (n 24), suggesting that increased distractibility may be associated with an abnormally strong cerebral orienting towards non-attended stimuli. A later negativity at around 300 ms, which increases in amplitude with stimulus repetition and may thus reflect the building up of a functional neuronal representation of the stimulus properties, was significantly smaller in the distractible than in the non-distractible children. These findings demonstrate that event-related potential measures may be useful in helping to understand the information processing found in distractible children.

Acoustic Stimulation↗
PubMed1999

The use of TL detectors in dosimetry of systemic radiation therapy.

A method for determining absorbed doses to organs in systemic radiation therapy (SRT) is evaluated. The method, based on thermoluminescent (TL) dosimeters placed on the patient's skin, was validated and justified through a phantom study showing that the difference between measured (TL dosimeters in the phantom) and derived (TL method) values is within 10%. Six radioimmunotherapy (RIT) patients with widespread intraperitoneal pseudomyxoma were also studied. In dose evaluations, special emphasis was on kidneys. In addition to the TL method, the absorbed doses to kidneys were calculated using MIRD formalism and a point dose kernel technique. We conclude that in SRT the described TL method can be used to estimate the absorbed doses to those critical organs near the body surface within 50% (1 SD).

Adult↗
PubMed1997

Brain aging: impaired coding of novel environmental cues.

Studies of the spatial memory capacities of aged animals usually focus on performance during the learning of new environments. By contrast, efforts to characterize age-related alterations in spatial firing information processing by hippocampal neurons typically use an environment that is highly familiar to the animals. In the present study we compared the firing properties of hippocampal neurons in young adult and aged rats as they acquired spatial information about new environmental cues. Hippocampal complex spike cells were recorded while rats performed a radial arm maze task in a familiar environment and then recorded again after many of the spatial cues were changed. After the change in the environment, in aged rats 35-42% of place fields retained their original shape and location with respect to the maze center, although they usually rotated to another arm. By contrast, all place fields in young animals either disappeared or appeared in a new location. Some of the new place fields appeared in the new environment during the first 5 min of exploration, whereas others needed more than 30 min to develop fully. In the familiar environment spatial selectivity of place cells was similar in young and aged rats. By contrast, when rats were placed into a new environment, spatial selectivity decreased considerably in aged memory-impaired rats compared with that of young rats and aged rats with intact memory performance.

Aging↗
PubMed1995

Oral contraceptive containing natural estradiol for premenopausal women.

An open multicenter trial was performed in six centers in Finland to study the efficacy, safety and acceptability of a new biphasic oral contraceptive pill containing natural estradiol and cyproterone acetate. The participants were 288 women with a mean age of 39.3 +/- 3.4 years (range 30-49) who were willing to use the new pill as their only contraceptive method. In total, 23% of the women were smokers. The cumulative experience was 2800 treatment cycles during the first year. The net 12-month continuation rate was 63%. One pregnancy occurred in a woman who lost 5 tablets in the second treatment cycle, which gives a 12-month cumulative pregnancy rate of 0.4%. Serum progesterone values, determined twice during the third treatment cycle, showed ovulation inhibition in 95% of women. There were no serious side effects. Intermenstrual bleeding was recorded by 35.5% and 24.5% of women at 3 and 12 months, respectively. The bleedings became scantier in most women and dysmenorrhoea disappeared. No changes were observed in total and high density lipoprotein cholesterol concentrations after 1 year. With the exception of intermenstrual spotting, the efficacy, safety and acceptability of the new pill was almost as good as that of the modern low dose oral contraceptives. This is the first pill containing natural estradiol that has gained clinical acceptance and which can also be prescribed for smokers over 35 years old until the climacteric.

Adult↗
PubMed1994

Changes in risk factors for unfavorable pregnancy outcome among singletons over twenty years.

OBJECTIVES: To examine the change in the prevalence and relative effect of pre-pregnancy risk factors for low birthweight and/or stillbirth and/or neonatal mortality over a period of twenty years. DESIGN: Two prospectively collected one year birth cohorts. SETTING: The two northernmost administrative districts of Finland. PATIENTS: A birth cohort for 1966 comprising 11905 singleton births and a cohort for 1985-86 containing a further 9247. MAIN OUTCOME MEASURES: Risk factors for poor pregnancy outcome. RESULTS: In twenty years the prevalence of low birthweight infants among singletons decreased from 4.2% to 3.1% and that of stillbirths and neonatal deaths from 2.4% to 0.9%. The impact of single marital status decreased and while maternal age < 19 years was not an independent risk factor, the age > or = 35 years related more to poor pregnancy outcome. The proportion of multiparous women was halved but multiparity had a protective influence on pregnancy outcome meanwhile the impact of primiparity decreased markedly. In spite of more effective health education, the prevalence of heavy smokers was 4 times higher in the 1980s as compared with the 1960s, and its impact on adverse outcomes increased, with odds ratio (OR) 1.72 (confidence interval (CI) 1.14-2.61) in 1966 and OR 2.15 (CI 1.61-2.88) in 1985-86. The number of mothers with a previous low birthweight baby was halved but the impact of low birth weight was still great in the latter cohort (OR 2.47; CI 1.64-3.71). The impact of an earlier stillbirth and/or neonatal death increased significantly, with an OR 1.53 (CI 1.10-2.14) in 1966 and OR 2.95 (CI 1.81-4.81) in 1985-86, but the number of mothers concerned was halved from that in 1966. CONCLUSIONS: The prevalence of pregnancies with an adverse outcome decreased markedly, as did the prevalence of many of the risk factors. The proportion of > or = 35 years old parturients and of heavy smokers increased. The impact of primiparity decreased, while that of a previous outcome as assessed from pre-pregnancy factors has not improved in these twenty years, especially where primiparous parturients are concerned.

Adult↗
PubMed1994

Combined intraperitoneal interferon alpha-2b and mitoxantrone in refractory ovarian cancer.

In a non-randomized clinical trial, combined intraperitoneal therapy with recombinant interferon alpha-2b (20-50 MU) and mitoxantrone (20-50 mg) was studied for recurrent ovarian cancer with ascites. Altogether 19 patients were treated. After primary operation, all patients had received intravenous chemotherapy, 16 of which included cisplatin. One patient had complete response, seven patients partial response, four no change and seven progressive disease. The mean duration of the responses was 5+ months (range 1-12), and mean survival time 4.5+ months (range 1-14+). Eight patients had side effects (flu-like symptoms, dyspnea, abdominal pain, vomiting, diarrhea, fever and bowel obstruction). It was concluded that the formation of ascites in refractory ovarian cancer can be reduced with intraperitoneal administration of interferon alpha-2b and mitoxantrone, with tolerable side effects.

Adult↗
PubMed1992

Chemosensitizing effect of an antiestrogen, toremifene, on ovarian cancer.

The chemosensitizing effect of an antiestrogen, toremifene, was studied on 2 human ovarian cancer cell lines in vitro and on 3 fresh surgical ovarian tumor explants with the aid of the subrenal capsule assay (SRCA). Also, 11 patients with secondarily drug resistant, recurrent gynecologic cancer (8 ovarian and 3 uterine cancers) were treated with 240 mg toremifene daily for 1 week before each course of cytostatics. Toremifene potentiated the effect of doxorubicin on both cell lines. This was also the case on 1 cell line that was not completely resistant to doxorubicin. The SRCA showed a clear potentiating effect of toremifene only on the tumor overtly resistant to the combination of cisplatin, doxorubicin, and cyclophosphamide. Of the 11 patients treated with toremifene and cytostatics, the response of 8 patients was evaluable: 3 had partial response, 3 no change, and 2 progressive disease. Toremifene seems to have a chemopotentiating effect on gynecologic drug-resistant tumors.

Aged↗
PubMed1992

Perinatal outcome of pregnancies complicated by vaginal bleeding.

OBJECTIVE: To examine the effect of first and/or second trimester vaginal bleeding on pregnancy outcome. DESIGN: A prospective one-year birth cohort. SETTING: Two northernmost administrative districts of Finland. PATIENTS: 8718 singleton pregnancies, of whom 807 (9.3%) reported bleeding during the first (601) and/or second trimester (206); light bleeding in 595 cases and heavy bleeding in 212. The remaining 7911 women served as a reference group. MAIN OUTCOME MEASURES: Low birth weight rate (LBW), preterm birth rate, congenital malformations and perinatal mortality rate. RESULTS: Bleeding was most frequent in women of more advanced age (> or = 35 years old), with previous miscarriages, with infertility problems or using an IUCD prior to the pregnancy. Parity, smoking and social status were not associated with bleeding. Caesarean section rate and placental complications during the third trimester and at delivery were more common among the bleeders than in the reference group. The LBW rate was three-fold among the bleeders and the preterm birth rate two-fold. The risk (OR) of a LBW infant among second trimester bleeders was 4.1 (95% CI 2.6-6.4), that of preterm birth 2.9 (95% CI 1.9-4.6), and that of congenital malformations 2.9 (95% CI 1.7-4.7). No association existed between bleeding and perinatal mortality. CONCLUSIONS: Bleeding during the second trimester indicates a poor pregnancy outcome and an increased risk of LBW, and preterm birth and/or congenital malformation.

Adult↗
PubMed1991

Transdermal oestrogen replacement therapy in a Finnish population.

In an open, multicentre study, transdermal administration of oestradiol (E2) by means of skin patches was investigated in a Finnish patient population suffering from typical post-menopausal symptoms. A total of 249 women applied a patch twice weekly for 6 months. Whereas 85% of the subjects were experiencing hot flushes and 83.5% sweating before therapy, only 5.7% and 11.8%, respectively, reported these symptoms at the end of the trial. Furthermore, 97.6%, 95.7% and 94.8% of the subjects reported that depression, headache and sleep disturbances, respectively, had disappeared during therapy. Skin irritation occurred in 18.2% of these predominantly fair-skinned women. Frequent sauna bathing did not interfere with the patch therapy. General acceptance of the treatment was excellent, 84.8% of the patients completing the treatment, of whom 78% were willing to continue the treatment after the trial. These results show that transdermal administration of E2 is effective in relieving post-menopausal symptoms. Local tolerability was good and the majority of the patients considered the transdermal treatment to be superior to their previous oral replacement therapy.

Administration, Cutaneous↗
PubMed1991

Occurrences of antibodies against Streptococcus pneumoniae, Haemophilus influenzae and Branhamella catarrhalis in middle ear effusion and serum during the course of acute otitis media.

The occurrence of IgG, IgM and IgA class antibodies against a type-specific capsular polysaccharide of Streptococcus pneumoniae (Pn) and against a whole cell antigen of Haemophilus influenzae (Hi) and Branhamella catarrhalis (Br) was studied using the ELISA method on middle ear effusion (MEE) samples of 85 patients and paired serum samples of 40 patients during the course of acute otitis media (AOM). Although specific antibodies to all of these three bacteria appeared in MEE during the course of an AOM episode, antibodies against the infecting bacteria of that particular AOM episode were more often prominent. The antibodies were also detectable in the MEE without simultaneous presence in the serum. The middle ear infection was prolonged more often if specific antibodies to the infecting bacterium could not be detected in the MEE obtained at the beginning of the AOM attack. The present study indicates that AOM caused by Pn, Hi or Br may induce both a systemic and a local production of specific antibodies against the causative organisms during the course of otitis media. The occurrence of such antibodies in MEE seems to play a major role in the resolution of AOM.

Acute Disease↗
PubMed1991

Secretory antibodies specific to Streptococcus pneumoniae, Haemophilus influenzae and Branhamella catarrhalis in middle ear effusion during acute otitis media.

The occurrence of specific secretory antibodies against the type-specific capsular polysaccharide of Streptococcus pneumoniae (Pn) and against the whole cell antigen of Haemophilus influenzae (Hi) and Branhamella catarrhalis (Br) were measured by the ELISA method in 211 middle ear effusion (MEE) samples of 85 children with acute otitis media (AOM) during the course of the disease. Antibodies against at least one of those bacteria were detected at the initial visit in 33.6% of the ears and later in 20%. All in all, such antibodies could be found in 50% of the ears during the follow-up. Pneumococcal secretory antibodies were found in 5 out of 116 ears only, anti-Hi antibodies in 52 and anti-Br antibodies in 42 ears. The specific secretory antibodies were detected against all these bacteria regardless of the bacterial etiology of the AOM attack in question. The AOM attack was prolonged more often if such antibodies were not found in the MEE sample taken at the initial visit. The appearance of such antibodies during the disease seemed to imply termination of the AOM episode in question. The conclusions of this study are that during an AOM attack a local production of antibodies in middle ear against the three most common bacteria. Pn, Hi and/or Br, causing AOM may be induced. The appearance of such antibodies in MEE seems to be beneficial for the resolution of AOM.

Acute Disease↗
PubMed1991

Hearing asymmetry among occupationally noise-exposed men and women under 60 years of age.

Interaural asymmetry of hearing thresholds at 4 kHz was analysed in four populations exposed to occupational noise. The left ear was found to be on average significantly worse than the right ear, among both the male and female subjects. In the male population the left ear was twice as often the worse ear as the right one. In the female population the corresponding ratio was 1.5. The average inferiority of the left ear increased as a function of the hearing threshold level. Among subjects with abundant shooting (reindeer herders) the average inferiority of the left ear was close to the average of all male subjects. Interaural difference increased as a function of the hearing threshold level, both among subjects with the left ear and subjects with the right ear being the worse one. In the male population the interaural difference was significantly greater in the former than in the latter group of subjects.

Adult↗